You’ve probably heard of the saying, “Drink to your health,” but when it comes to safeguarding your fertility, moderation is definitely key in alcohol consumption. Women usually swear off alcohol once they find out they’re with child, but in truth, it is best for them to abstain from alcohol as soon as they’re ready to start a family. And it’s not just women who should keep tabs on their alcohol intake!

A growing number of scientific studies have shown that as little as one alcoholic drink a day can lead to detrimental effects in one’s chances at conceiving. For example, according to a study published in the American Journal of Epidemiology in 2004, alcohol can shorten a woman’s follicular phase and menstrual cycle.

Meanwhile, a 2009 study conducted at Harvard University found that in couples undergoing IVF, women who drank more than six units of alcohol per week were 18% less likely to conceive, while men were 14% less likely. This finding was supported by a study published in 2011 in the Annals of Epidemiology. Entitled ‘Alcohol, Smoking, and Caffeine in Relation to Fecundability, with Effect Modification by NAT2,‘ it concluded that alcohol intake was significantly associated with reduced fertility.

The study, which followed 319 women over an average of 8 menstrual cycles and 124 pregnancies, discovered that women who drink alcohol once a day can experience a 30% reduction in fertility, while those who took more than one alcoholic drink a day experienced a 50% reduction.

Another study published in 2011, entitled ‘Effect of alcohol consumption on in vitro fertilization,’ published in the Journal of Obstetrics and Gynecology found that drinking before becoming pregnant can lower live birth rates by up to 21% in IVF patients.

This prospective cohort study involved multicycle analyses with final models adjusted for potential confounders that included cycle number, cigarette use, body mass index, and age. From the 2,545 couples studied, it was found that women who drink at least four drinks per week had 16% less odds of a live birth rate compared with those who consumed less alcohol.

Although there is a link between drinking and fertility, researchers still do not know exactly how alcohol impairs fertility, says Dr Anthony Rutherford, a consultant in reproductive medicine and Chairman of the British Fertility Society.

However, it is clear to researchers that alcohol doesn’t just affect female fertility. According to Dr Patrick O’Brien, spokesperson for the Royal College of Obstetricians and Gynaecologists, “Excessive alcohol lowers testosterone levels and sperm quality and quantity in men. It can also reduce libido, and cause impotence.”

Fortunately, however, any damaging effects alcohol has on fertility can be quickly reversed by reducing alcohol intake or abstaining from it, as well as getting proper nutrition and leading a healthier lifestyle. Therefore, before you raise your glass next time, spare some thought over how it can stand in the way of your goals of starting a family.